ESE's works engine tuner

[Flettner]

I think the bike you are referring to was called The Rat.

yes the rat bike😆

[Pursang]

What video engine was i watching what i seen looked like an opposed twin?

Early lightweight cycle-car powered by opposed twin.....
.

[Flettner]

Early lightweight cycle-car powered by opposed twin.....
.

Nice------

[husaberg]

Early lightweight cycle-car powered by opposed twin.....
.

Nice------

Oh i see now the Chinese are doing Siamese exhausts as well

[katinas]

Use a Vt250 gearbox nice ratios strong gears quite narrow, millions made available from any wrecker in any country. nice clutch, available in 5 or 6 speeds as well. also the same gearbox is used on the MVX250 an fthe CBR250
they have an intersting gearshift set up though almost planetary. available either push or pull left or right clutch.

Attachment 342385Attachment 342386

Interesting article about VT250 Turbo version 53Hp and racing NR 250 oval, but looks like on the illustration some mistake about NR power, maybe it could be 103 hp 18000rpm., not 53hp, like on the street version.

https://japan.young-machine.com/2018/10/14/10926/

[husaberg]

Interesting article about VT250 Turbo version 53Hp and racing NR 250 oval, but looks like on the illustration some mistake about NR power, maybe it could be 103 hp 18000rpm., not 53hp, like on the street version.

https://japan.young-machine.com/2018/10/14/10926/

Cheers i think this was where i first seen about it.
https://cx500forum.com/forum/cx500-c...her-turbo.html

[katinas]

Want to say thanks again to this forum.
Boy show good result in today s MX65 World Cup qualification, with rounded piston in 4th place.
Most modification on the engine was from this Kiwi thread.
Thanks

[Frits Overmars]

Want to say thanks again to this forum.
Boy show good result in today s MX65 World Cup qualification, with rounded piston in 4th place.
Most modification on the engine was from this Kiwi thread.
Thanks

Thank you for the feedback Katinas .

[TZ350]

Boy show good result in today s MX65 World Cup qualification, with rounded piston in 4th place.

............. Brilliant....

[TZ350]

Very satisfying to see Blair on Team ESE's GP-NSR110 being total dominant in the prelim race and taking out a at Hampton Downs today.

DNF'd later with a massive slide into the kitty litter.

[F5 Dave]

Looks a little wet there Rob

[TZ350]

Looks a little wet there Rob

Yep, raining cats and dogs at one point.

[katinas]

Sunday warm up 6th place, but race with little drama.

After first fall in race 1, boy cant start up engine too quickly and ended in 39th place.
In race 2, after two falls, finished in 9th place.
Nice experience and Italian fans was amazing.
After two weeks time, final all European MX65 championship round.

Just want to say that after dyno tests we stick to std KTM exhaust pipe and std reed cage.
We tested HGS pipe and V force reed block, but both work in the same way.
Max power was same like with std.
Over revs with little higher power.
But too much lost at mid range.
Maybe with rounded piston ( 1mm and knife sharp at C ), HGS exhaust tailpipe is too small, but we didnt test HGS with std piston.

We tried rounded piston (with other mod) on other three racers KTM engines, ( two 50, one 65, one 125) and they all were very happy. One
SX65 engine goes to Ireland championship and after the first race was surprises how it goes so well with std pipe.
I decide to try this on my sons Yamaha Why scooter, with intention not to change any original parts. Just modified head, rounded std piston, wider than crankcase intake to C on cast iron cylinder ( aprox 1.5 mm step on crankcase ) std exhaust and speed goes up from 60 to 75 kmh with much stronger acceleration.

Thanks again Frits about this idea and many others about nice two stroke things.

[Frits Overmars]

My pleasure Katinas .

[wobbly]

Katinas - with 1mm radius how much did you drop the cylinder , and with no radius on the boost where does its timing end up
compared to previously.
I have tested 0.75 and 1,5 radius with lowering the cylinder 1/2 the radius.
But have not tested the uncut boost port idea - want to copy what you have found to work already.